Florida Rep. Bill Young, the House’s longest-serving Republican and a titan among its defense hawks, will step down next year at the end of his term, he said Wednesday.

There were many reasons for his decision, he told his hometown newspaper, the Tampa Bay Times.

“I don’t know that I would pick out one thing. It’s a lot of things. My family, my job, my rehabilitation from my back,” said Young, 82.

The announcement caps a congressional career that began in 1970, when Young was first elected to the House. A prolific earmarker, he holds a seat on the Appropriations Committee and chairs its defense subcommittee. For years, the perch gave him broad power over military spending.

“It’s obviously a loss, but an expected one,” said one defense industry source, requesting not to be identified to offer a candid take. “He has been a champion for the department, for men and women in uniform, and for industry. He will be missed.”

“On the other hand,” the source added, “it will be good to get some new blood in the chair.”

Another source, a longtime defense lobbyist, said Rep. Rodney Frelinghuysen was expected to succeed Young in the next Congress as head of the Appropriations defense subcommittee, assuming Republicans maintain control of the House. Frelinghuysen, from New Jersey, is the defense panel’s No. 2 Republican.

Young’s suburban St. Petersburg seat is likely to be competitive in 2014. President Barack Obama narrowly won the district last year and in 2008, and Democrats have long said they planned to target the seat once Young retired.

Democrat Jessica Ehrlich, an attorney who received 42 percent of the vote when she ran against Young in 2012, has already launched a campaign. Republicans identify state Sen. Jack Latvala and state Rep. Dana Young as possible candidates.

Young has said that he would support his wife, Beverly, or son, Bill Young II, succeeding him. Beverly Young has been active on behalf of veterans’ causes; Bill Young II has been mentioned as a possible candidate for the state House of Representatives.

“If my wife were elected to Congress, Congress would never be the same,” Young told a Florida TV station in 2010. “Billy would be a good member of Congress. He’s smart. He understands political issues — he understands them even better than I do on some occasions.”

Despite his support for defense vendors, Young broke with traditional hawks in his party. In 2012, he called for the withdrawal of troops from Afghanistan, saying: “I just think we’re killing kids that don’t need to die.”

More recently, the Tampa Bay Times said Young “seemed increasingly out of step” with the polarized climate in Washington, noting that he was one of a handful of House Republicans voicing support for a “clean” continuing resolution — stripped of provisions that would undermine Obamacare — to end the government shutdown.

House Speaker John Boehner “withstood the pressure for a long time,” Young told the newspaper of the Ohio Republican’s struggles with the conservative wing of the party. “He finally has agreed to the outspoken minority of his conference. And they’re pretty much in charge right now.”

Young, who often raised the ire of anti-earmark groups, served for nine years in the Army National Guard, plus six years as a reservist, according to his official biography.

The district brought in more than $121 million in defense contracts during the 2012 fiscal year and is a major hub for defense giant Lockheed Martin, which builds components there for its fighter jets.

Young has also been a major advocate for MacDill Air Force Base, home to several key units, including U.S. Central Command, U.S. Special Operations Command and the Air Force’s 6th Air Mobility Wing.